KILLADREENY, or KILLADREENAN, a chapelry (ancient), forming part of the parish of NEWCASTLE, county of WICKLOW, and province of LEINSTER, 1 mile (S. by E.) from Newtown-Mount-Kennedy, on the road from Dublin to Wexford: the population is returned with the parish. It contains 547 statute acres, under an improving system of agriculture. Mount John is the seat of Graves Chamney Archer, Esq.; and Killadreenan, of Alderman C. P. Archer. This chapelry is in the diocese of Dublin and Glendalough, and is annexed to the rectory of Newcastle. The ruins of the ancient chapel stand in the centre of a burial-ground, which is enclosed and is still used as a place of interment for the Byrnes, Tooles, Coolins, and other ancient R. C. families. In the R. C. divisions it forms part of the union or district of Kilquade.